<h3>Tree9</h3>
<!-- 
  nzShowIcon       是否展示 TreeNode title 前的图标，没有默认样式
  nzExpandedIcon   自定义展开图标 这里又直接指向了一个模板
  let-node         没看懂
  nz-icon          代表用的是nz的图标
  nzType           图标的样式，但是写的时候要写"'样式'"，注意单引号
 -->

<nz-tree [nzData]="nodes" nzShowIcon [nzExpandedIcon]="expandedIconTpl">
  <ng-template #expandedIconTpl let-node>
    <i nz-icon [nzType]="'setting'" class="ant-tree-switcher-icon"></i>
  </ng-template>
</nz-tree>
<nz-tree [nzData]="nodes" nzShowIcon [nzExpandedIcon]="mutiExpandedIconTpl">
  <ng-template #mutiExpandedIconTpl let-node>
    <!-- 如果不是叶子节点 节点可以扩展 就是folder-open 否则就是folder -->
    <i *ngIf="!node.origin.isLeaf" nz-icon [nzType]="node.isExpanded ? 'folder-open' : 'folder'"
      class="ant-tree-switcher-line-icon"></i>
    <i *ngIf="node.origin.isLeaf" nz-icon nzType="file" class="ant-tree-switcher-line-icon"></i>
  </ng-template>
</nz-tree>

<!-- 自己写的 -->
<h3>自己写的</h3>
<nz-tree [nzData]="nodes" nzShowIcon [nzExpandedIcon]="tubiao">
  <ng-template #tubiao let-node>
    <!-- 如果不是叶子节点 节点是展开状态 就是menu  否则就是scan -->
    <i *ngIf="!node.origin.isLeaf" nz-icon [nzType]="node.isExpanded ? 'menu' : 'scan'"
      class="ant-tree-switcher-line-icon" nzTheme="outline"></i>

  </ng-template>
</nz-tree>